Study of BOR-60 reactor fuel element performance

Described are the test conditions and the results of the material researches of a series of the fuel element packets irradiated in the BOR-60 reactor up to burning-out of 6 to 11% of heavy atoms. Considered are the states of the jackets made of the 0Kh16N15M3B and 1Kh18N10T steels and fuel in the form of sintered uranium dioxide sleeves, effect of the irradiation parameters on the mechanical properties of the jacket, variation of the fuel element diameter and jacket density, accidents involving the breakdown of the fuel element jackets. It is shown that variation of the jacket diameter is due mainly to steel swelling. After irradiation up to burning-out of 8 - 11% of heavy atoms, the plasticity of the jackets has decreased by several tenth fractions of percent. It has been revealed that corrosion interaction of the fuel and jacket extends to the depth of up to 70 μm. It is concluded that the sealed fuel elements remain serviceable up to burning-out of 10 - 11% of heavy atoms